1. Field of the Invention
The invention relates to a jacking device, and, more particularly, to a jacking device and method for use with a structural member of a building, which is useful for incrementally raising or lowering the structural member and/or members simultaneously.
One of the most serious problems that can face an owner of a structure is that the ceiling is too low or too high. This problem commonly occurs in commercial structures, such as warehouses. Once the structure has been built, it may be discovered, for example, that the ceiling is too low to permit storage of taller items. Thus, it may be necessary to raise or lower the ceiling.
This problem can also occur in structures with multiple stories. In these situations, the ceiling that needs to be raised may also be the roof, or the floor of another story.
The ability to increase the overall height of the structure may be limited by, for example. building codes when the structure is at or near a maximum height. In situations such as these, in order to increase the distance between the floor and the ceiling, the floor must be lowered.
Moreover, it may be desired to raise an entire side of a floor or ceiling, or, indeed, the entire floor or ceiling, in a coordinated manner.
There are also occasions during which it is desirable to either raise or lower other structural members. For example, a roof may be raised and positioned prior to being secured to a new building.
2. Description of the Related Art
It is known that a roof may be raised as an entire structure. Systems and devices for raising an entire roof structure are known, and are disclosed, for example, in U.S. Pat. No. 4,980,999, issued to Robert S. Terenzoni, and U.S. Pat. No. 2,305,906, issued to William Herbert Smith. These systems and devices, however, are unsuitable for the purpose of increasing or decreasing the distance between a roof or ceiling.
Hydraulic jacks associated with building structures are generally known. One such jack is shown in U.S. Pat. No. 4,715,760, issued to Ervin R. Browning. A pneumatic cylinder rests on a pin at a selected pair of holes so as to initially manually position the cylinder. The piston rod then is extended, and remains extended at a selected vertical position. Unfortunately, the Browning device is primarily useful for such relatively light building components such as cabinets and ceiling frames, and could benefit from improved safety. Moreover, the degree of extension is determined by the length of the piston.
A jack using a pin and hole height adjustment feature is also known, as shown in U.S. Pat. No. 4,624,447, issued to Thomas L. Richmeier. As in the Browning patent, the piston rod is extended until the selected position is reached. Although the Richmeier device is versatile, it has some of the disadvantages discussed above, and further has the disadvantage of having many parts.
Other conventional jacking devices for raising individual components of a building are known. For example, U.S. Pat. No. 4,027,802, issued to Francis Reynolds, discloses a positioner for use with building panels to be positioned adjacent to a ceiling or wall framework. U.S. Pat. No. 3,438,514, issued to Gordon D. Bose, discloses a powered lift for elevating sheetrock to a horizontal position adjacent to a ceiling. U.S. Pat. No. 3,365,080, issued to William F. Crull, discloses another apparatus for lifting and supporting panels in a horizontal position, such as ceiling boards held in place while being secured to a ceiling structure. These jacking devices have limitations and disadvantages similar to those already discussed.
A variety of apparatuses for inducing synchronization in jacking devices are known, disclosed in U.S. Pat. No. 4,661,749, issued to Walter Finkbeiner. Even when used with conventional jacking devices, the usual limitations and disadvantages of the conventional jacking devices are not overcome.
Thus, there is a need for a structural member jacking device with improved safety and ease of use, while at the same time providing a large range of extensibility and capable of being incrementally raised or lowered. There is also a need for a structural member jacking device which can be left in place for an extended period of time, once the desired positioning is achieved. There is a further need for a structural member jacking device with which a plurality of the structural member jacking devices may be raised or lowered at more than one point in a synchronized manner.